Chapter 17 – Mycobacterial Disease in Patients with HIV Infection

This chapter reviews the important aspects of the interplay of HIV infection with mycobacteria, particularly focusing on features that are clinically relevant. HIV infection has been one of the principal reasons for the recent increase in incidence of mycobacterial diseases worldwide. Understanding TB in patients infected with HIV is important from many standpoints. First, among tuberculosis-infected individuals, immunosuppression because of HIV is the greatest known single risk factor for progression to TB disease. Second, TB differs from other HIV-related infections in that it is spread respiratorily from person to person both in normal and immunocompromised hosts. There is, therefore, significant potential for an aerosol-transmitted disease such as TB to spread rapidly among HIV-infected persons exposed to each other and from them to non-HIV infected contacts. Finally, mycobacterial disease in HIV-infected patients often presents with an atypical clinical picture: tuberculin skin anergy is common, the chest radiograph is often atypical, and there is a high incidence of extrapulmonary and disseminated disease, all contributing to confound the diagnosis, which may easily be missed unless these features are appreciated.